Fluid Path between the Outer Surface of a Tool and an Expandable Blade

ABSTRACT

In one aspect of the invention, an expandable tool for an earth boring system comprises a through bore configured to accommodate drilling fluid. A blade is configured to extend and retract out of an outer surface of the tool. A secondary fluid pathway connects the bore with an interface between the outer surface of the tool and a surface of the blade. The secondary pathway directs drilling fluid through the interface.

BACKGROUND OF THE INVENTION

The present invention relates to the fields of downhole oil, gas, and/or geothermal exploration and more particularly to the fields of expandable tools for downhole exploration. A variety of expandable tools are to enlarge the diameter of a wellbore and/or to stabilize a tool string during drilling operations. Expandable tools of this type may contain arms or blades which extend from the sides of a tool string and contact an earthen formation. Examples of these types of expandable tools are described in the following prior art documents.

U.S. Pat. No. 7,314,099 to Dewey et al., which is herein incorporated by reference for all it contains, discloses an expandable downhole tool comprising a tubular body having an axial flow bore extending there through, at least one moveable arm, and a selectively actuatable sleeve that prevents or allows the at least one moveable arm to translate between a collapsed position and an expanded position. A method of expanding the downhole tool comprises disposing the downhole tool within the wellbore, biasing the at least one moveable arm to a collapsed position corresponding to an initial diameter of the downhole tool, flowing a fluid through an axial flow bore extending through the downhole tool while preventing the fluid from communicating with a different flow path of the downhole tool, allowing the fluid to communicate with the different flow path by introducing an actuator into the wellbore, and causing the at least one moveable arm to translate to an expanded position corresponding to an expanded diameter of the downhole tool.

U.S. Patent App. 2008/0128175 to Radford, et al., which is herein incorporated by reference for all that it contains, discloses an expandable reamer apparatus for drilling a subterranean formation including a tubular body, one or more blades, each blade positionally coupled to a sloped track of the tubular body, a push sleeve and a drilling fluid flow path extending through an inner bore of the tubular body for conducting fluid there through. Each of the one or more blades includes at least one cutting element configured to remove material from a subterranean formation during reaming. The push sleeve is disposed in the inner bore of the tubular body and coupled to each of the one or more blades so as to effect axial movement thereof along the track to an extended position responsive to exposure to a force or pressure of drilling fluid in the flow path of the inner bore.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, an expandable tool for an earth boring system comprises a through bore configured to accommodate drilling fluid. A blade is configured to extend and retract out of an outer surface of the tool. A secondary fluid pathway connects the bore with an interface between the outer surface of the tool and a surface of the blade. The secondary fluid pathway directs drilling fluid through the interface.

The bore may be formed in a mandrel and the secondary fluid pathway may connect an inner and outer circumference of the mandrel. The secondary fluid pathway may comprise an outlet formed in the bore, which may extend from the outlet to an outer sleeve. The pathway may travel along the outer circumference of the mandrel to the interface. The pathway may also be configured to direct drilling fluid to clear debris from the interface. The outer sleeve is configured to slide along the mandrel, wherein sliding the sleeve is configured to extend the blade. An inside face of the sleeve and the outer circumference of the mandrel direct fluid to the interface.

The blade may be configured to connect to the outer surface of the tool through a groove, wherein the groove is incorporated in the interface. The secondary fluid pathway may direct drilling fluid through the groove. The blade may be configured to expand independently of drilling fluid movement.

A piston assembly may reside in the secondary fluid pathway with a piston chamber formed in the piston assembly. The piston chamber may comprise a nozzle ring which may be configured to travel along the outer surface of the mandrel. Sliding the nozzle ring may expand the blade. An internal nozzle may be formed in the nozzle ring configured to allow fluid to exit the piston chamber through the nozzle ring. The internal nozzle comprises a stopping mechanism configured to halt fluid flow through the piston. The piston chamber is configured to hold a portion of the drilling fluid. An aperture may lie within the secondary fluid pathway, wherein the aperture may direct the fluid to the piston chamber located within the thickness of the mandrel wall. The piston assembly may comprise a seal located on an outside width of the nozzle ring configured to stop fluid flow between the piston's width and an inner surface of the chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 discloses an orthogonal view of an embodiment of a tool string.

FIG. 2 a discloses a perspective view of an embodiment of an expandable tool.

FIG. 2 b discloses a perspective view of an embodiment of an expandable tool.

FIG. 3 discloses a cross-sectional view of a secondary fluid path.

FIG. 4 discloses a cross-sectional view of an embodiment of an expandable tool.

FIG. 5 discloses a cross-sectional view of another embodiment of an expandable tool.

FIG. 6 a discloses a cross-sectional view of another embodiment of an expandable tool.

FIG. 6 b discloses an orthogonal view of an embodiment of a nozzle ring.

FIG. 7 discloses a perspective view of another embodiment of an expandable tool.

FIG. 8 discloses a perspective view of another embodiment of an expandable tool.

FIG. 9 discloses a perspective view of another embodiment of an expandable tool.

FIG. 10 discloses a cross-sectional view of another embodiment of an expandable tool.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 discloses an orthogonal view of an embodiment of a drilling operation comprising a drilling derrick 101 that is supporting a tool string 100 inside a borehole 102. The tool string 100 may comprise an expandable tool configured to rotate in the borehole 102. Rotating the tool string 100 may also rotate a drill bit 104 and cause the drill bit 104 to degrade a bottom of the borehole 102. Degrading the borehole 102 may shake the tool string 100 and accompanying parts about an interior of the borehole 102. The expandable tool may be configured to limit the shaking by extending and stabilizing the tool string 100.

FIG. 2 a discloses an embodiment of the expandable tool 200 in a retracted position. The expandable tool 200 may need a blade 202 retracted during assembly of the tool string 100. An outer diameter of the refracted tool 200 may be similar to an outer diameter of the tool string 100. The expandable tool 200 may also be retracted during insertion and withdrawal of the tool string 100 from the borehole 102. Also, when the expandable tool 200 is moving through narrow portions of the borehole 102, the expandable tool 200 may retract to save the blade 202. This may protect the tool's 200 components.

FIG. 2 b discloses an embodiment of the expandable tool 200 in an extended position. Stabilizing the tool string 100 may dislodge debris or aggregate from the borehole wall 102. Some of the debris may fall onto the expandable tool 200, more precisely into an interface 321 between the blade 202 and a mandrel 203. This may hinder the ability of the expandable tool 200 to extend the blade 202 and stabilize the tool string 100. The tool string 100 may be configured to direct drilling fluid from a top to a bottom of the tool string 100. In some embodiments the blade may be configured to extend and retract independently of drilling fluid movement. The expandable tool may be in contact with a moving mechanism that causes the blade to extend and retract. In some embodiments, surface equipment may be used to send commands to the expandable tool that dictate the extension and refraction of the tool's blade.

FIG. 3 discloses a cross-sectional view of the mandrel 203 and the blade 202. An interface 321 may be formed in a connection between the blade 202 and the mandrel 203. Arrows 300 in the interface 321 represent fluid that traverses through the expandable tool 200. The fluid may exit the tool 200 through the interface 321 as depicted in FIG. 3. The fluid may be configured to expel debris 301 located in the interface 321 from the expandable tool 200.

FIG. 4 discloses a cross-sectional view of an embodiment of the expandable tool 200. A secondary fluid pathway 421 may be formed in the expandable tool 200. The secondary fluid pathway 421 may be configured to route drilling fluid away from the through bore 404 and into an interface 321 between the blade 202 and the mandrel 203. The blade 202 may be configured to connect to the tool 200 through a groove 418 that may be located on an inside of the blade 202 and on an outer surface of the mandrel 409. The drilling fluid may be directed to the interface 321 and dislodge debris trapped in the interface 321. This may result in the expandable tool 200 extending the blade 202 and stabilizing the tool string 100 in the borehole 102.

A piston chamber may be located within the secondary fluid pathway 421. The piston chamber may comprise a nozzle ring 425 and an aperture 410. The nozzle ring 425 may be located radially outward the aperture 410 and be configured to slide along the outer circumference of the mandrel 409. The nozzle ring may be connected to the plurality of blades wherein sliding the nozzle ring along the mandrel 203 may extend the blade. Both the nozzle ring 425 and the aperture 410 may be configured to contact the drilling fluid flowing through the fluid pathway 421.

The secondary fluid pathway 421 may comprise an outlet 413 formed in the bore located in the mandrel 203. A ball may be dropped into the drilling fluid from the top of the tool string 100 and descend through the tool string 100 until it reaches a ball catch. The ball may engage the catch and open the outlet 413. The outlet 413 may be configured where opening the outlet 413 directs the drilling fluid from the bore 404. The drilling fluid may then flow through the secondary fluid pathway 421.

In some embodiments, the outlet may open electronically. For example, a downhole telemetry system, such as wire pipe, may be in communication with the values or actuators controlling the valves. Power and/or date controlling the valves or actuators may cause the valves or open or close. Some embodiments may include downhole power sources such as batteries or mud driven generators. In some cases, downhole electronics or intelligence may control the valves.

The secondary fluid pathway 421 may be configured to direct the drilling fluid to clear debris 301 from the interface 321. The fluid pathway 421 may direct the drilling fluid to travel through the interface 321 between the mandrel 203 and the blade 202 and contact any debris 301 fixed in the interface 321. The fluid and the debris 301 may exit the expandable tool 200 through the interface 321. The fluid may force the debris 301 out of the interface 321, which may result in clearing the interface 321 and allowing the expandable tool 200 to freely extend and retract the blade 202.

The secondary fluid pathway 421 may be configured to continually contact the drilling fluid while the expandable tool 200 is extended. The drilling fluid may comprise a variety of abrasive particles. A wear resistant material may be applied to the secondary fluid pathway 421 to help reduce wear. The wear resistant material may increase the endurance of the secondary fluid pathway 421.

An aperture 410 may be formed in the mandrel 203. The secondary fluid pathway 421 may comprise the aperture 410, configured to lead the drilling fluid from the inner 411 to the outer circumference 411. The aperture 410 may be formed in the expandable tool 200 above the blade 202. The nozzle ring 425 may be configured to direct the drilling fluid to the outer circumference of the mandrel 409. After contacting the nozzle ring, the secondary fluid pathway 421 may lead the drilling fluid from the outer circumference of the mandrel 409 to the interface 321. The interface 321 formed between the expandable tool 200 and the blade 202 may be adjacent to the mandrel 203.

An outer sleeve 217 may be disposed on the outer circumference of the mandrel 409 with the blade 202 formed in an opening of the sleeve 217. The outer sleeve 217 may assist in extending and retracting the blade 202. The secondary fluid pathway 421 formed in the tool 200 may connect the outlet 413 formed in the bore 404 to the outer sleeve 217. The drilling fluid that exits the bore 404 through the outlet 213 may travel through the secondary fluid pathway 421 until reaching the sleeve 217.

The outer sleeve 217 may be configured to slide along the outer circumference of the mandrel 409, wherein sliding along the mandrel 203 engages the groove 418 on the outer sleeve 217 and on the blade 202. Engaging the groove 418 may extend the blade 202.

FIG. 5 discloses a cross-sectional view of the expandable tool 200 with the secondary fluid pathway 421 formed in the tool 200. Arrows 503, 504 represent the flow of drilling fluid as it travels along the secondary fluid pathway 421 toward the interface 321. The drilling fluid may continuously exit the interface 321 during the expandable tool's 200 operation.

An inner face of the outer sleeve 217 and the outer circumference of the mandrel 409 may also form a portion of the secondary fluid pathway 421. This portion of the fluid pathway 421 may be located adjacent to the interface 321, extending from a bottom of a nozzle ring 501 to the interface 321. The outer surface of the mandrel 409 and the inner face of the outer sleeve 217 may be configured to direct drilling fluid to the interface 321.

FIGS. 6 a and b collectively discloses a piston assembly 625 disposed about the outer circumference of the mandrel 409. The piston assembly 625 may comprise a piston chamber 601. A nozzle ring 425 may be disposed within the piston chamber 601. The piston chamber 601 may be configured to hold a portion of the drilling fluid. A seal 603 may be located on an outside width of the nozzle ring 425. The nozzle ring 425 may comprise a plurality of openings 604 evenly spaced along the inner diameter of the nozzle ring 425 corresponding to the aperture 410 in the mandrel 203. An internal nozzle 606 may be placed in the nozzle ring 425 and traverse through the nozzle ring 425.

The nozzle ring 425 may be configured to increase a pressure in the drilling fluid. Drilling fluid may enter the piston chamber 601 until sufficient pressure is built up to force the nozzle ring 425 along a span of the expandable tool 200. The nozzle ring 425 may expand the piston chamber 601 by shifting along the mandrel 203. An equilibrium pressure may eventually be reached on two sides of the nozzle ring 425 and reaching the equilibrium pressure causes the shifting to halt. The blade 202 may be connected to the nozzle ring 425 such that shifting the nozzle ring 425 along the mandrel 203 may force the expandable tool 200 to extend the blade 202. When the outlet 413 is closed and the drilling fluid stops flowing through the secondary fluid pathway 421, external forces on the blade 202 may cause the blade 202 to retract into the outer sleeve 217.

The nozzle ring 425 may be placed within a section of the secondary fluid pathway 421. The nozzle ring 425 may be positioned on the outer circumference of the mandrel 409, contacting the mandrel 203 and forming a wall in the piston chamber 601. A plurality of openings 604 may be formed in the nozzle ring 425 and configured to receive the drilling fluid exiting the aperture 410. The plurality of openings 604 may direct the drilling fluid into the piston chamber 601.

The internal nozzle 606 located in the nozzle ring 425 may be configured to contact the drilling fluid. The internal nozzle 606 may be located inward the seal 603. The internal nozzle 606 may connect an inside of the piston chamber 601 with a part of the secondary fluid pathway 421 that continues on an outside of the piston chamber 601. A portion of the drilling fluid that enters the piston chamber 601 may exit the piston chamber 601 through the internal nozzle 606. This may allow the drilling fluid to continue through the secondary fluid pathway 421 toward the interface 321.

The seal 603 located on the outside of the nozzle ring 425 may assist in blocking the drilling fluid from exiting the piston chamber 601 through an association between an outer width of the nozzle ring 425 and an inner wall of the piston chamber 601. The seal 603 may comprise an elastic substance configured to fluidly seal the piston chamber 601 and the nozzle ring 425. The seal 603 may be configured to slide along the inner wall of the piston chamber 409 adjacent to the sliding nozzle ring 400.

The piston assembly 625 may comprise a stopping mechanism. The stopping mechanism may be configured to halt drilling fluid flow through the nozzle 606. During operation the drilling fluid may exit the piston chamber 601 through the nozzle 606 in the nozzle ring 425 until the stopping mechanism is employed. The stopping mechanism may be utilized when pressure is needed inside the piston chamber 601 to extend the blade 202.

FIG. 7 discloses a perspective view of an embodiment of the expandable tool 200 in a refracted position. The interface 321 between curved portions 700 on the blade 202 and the mandrel 203 may comprise a plurality of crevices 701. The secondary fluid pathway 421 may be configured to direct drilling fluid through the plurality of crevices 701, causing the drilling fluid to exit the interface 321 by way of the plurality of crevices 701. The drilling fluid may dispel debris that has entered into the plurality of crevices 701.

The groove formed between the blade and the expandable tool 418 may be incorporated into the interface 321. The groove 418 may be angled to assist in extending and/or retracting the blade 202. In some embodiments, the groove may have a buttressing effect configured to help lock the blade in the extended position.

FIG. 8 discloses a perspective view of an embodiment of the tool 200. The interface 321 formed by the groove 418 may comprise a plurality of crevices 700 where the plurality of crevices 700 consists of places where the groove does not fit together perfectly. The plurality of crevices 700 may be located on sloped portions of the plurality of crevices 700. The drilling fluid may traverse through the secondary fluid pathway 421 and exit the interface 321 through the plurality of crevices 700 located in the sloped portions of the interface 321. The drilling fluid may force out any loose debris or aggregate that may have entered into the plurality of crevices 700.

FIG. 9 discloses a perspective view of an embodiment of the expandable tool 200 and the drilling fluid exiting the tool 200. As the fluid exits the interface 321 the fluid may force debris and aggregate out of the interface 321. The interface 321 between the blade 202 and the mandrel 203 may comprise adjacent surfaces 901, 902. The adjacent surfaces 901, 902 may allow easier production of the expandable tool 200, a smoother exit for the drilling fluid, and the extension and retraction of the blade 202 with less debris wedging in the interface 321 between the surfaces 901, 902.

FIG. 10 discloses a cross-sectional view of another embodiment of the expandable tool 200. In this embodiment, the secondary fluid pathway 1001 travels almost directly from the port 413 to the interface 321. The drilling fluid may flow through this pathway 1001 with less force than in previous embodiment and still expel debris from the interface 321. The length of the secondary fluid pathway 1001 may be minimized to decrease manufacturing and assembling complexity.

In some embodiments, the drilling fluid passes directly from the outlet to the interface. The secondary fluid path, including at the interface, may be coated, lined, titled, and/or protected by a wear resistant material. This material may include a cemented metal carbide, ceramics, boron cubic nitride, natural or synthetic diamond, sintered, polycrystalline diamond, vapor deposited polycrystalline diamond, aluminum oxide, or combinations thereof.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention. 

1. An expandable tool for an downhole tool string component, comprising; a through bore configured to accommodate drilling fluid; a blade configured to extend and retract out of an outer surface of the tool; and a secondary fluid pathway connects the bore with an interface between the outer surface of the tool and a blade surface; wherein the secondary pathway directs drilling fluid through the interface.
 2. The tool of claim 1, wherein the bore is formed in a mandrel and the secondary fluid pathway connects an inner and outer circumference of the mandrel.
 3. The tool of claim 2, wherein the secondary fluid pathway travels along the outer circumference of the mandrel to the interface.
 4. The tool of claim 1, wherein the secondary pathway comprises an outlet formed in the bore.
 5. The tool of claim 4, wherein the pathway extends from the outlet to an outer sleeve.
 6. The tool of claim 5, wherein the outer sleeve is configured to slide along the mandrel, wherein sliding the sleeve along the mandrel is configured to extend the blade.
 7. The tool of claim 5, wherein an inside face of the sleeve and the outer circumference of the mandrel direct fluid to the interface.
 8. The tool of claim 1, wherein the secondary pathway is configured to direct drilling fluid to clear debris from the interface.
 9. The tool of claim 1, wherein the blade is configured to expand independently of drilling fluid movement.
 10. The tool of claim 1, wherein the blade is configured to connect to the outer surface of the tool through a groove, wherein the groove is incorporated in the interface.
 11. The tool of claim 1, wherein a piston assembly lies in the secondary fluid pathway.
 12. The tool of claim 11, wherein a piston chamber is formed in the piston assembly, wherein the piston chamber comprises a nozzle ring.
 13. The tool of claim 12, wherein an aperture lies within the secondary fluid pathway, wherein the aperture directs the fluid to the piston chamber located within the thickness of the mandrel wall.
 14. The tool of claim 12, wherein an internal nozzle is formed in the nozzle ring, wherein the internal nozzle is configured to allow fluid to exit the piston chamber through the nozzle ring.
 15. The tool of claim 14, wherein the internal nozzle comprises a stopping mechanism configured to halt fluid flow through the piston.
 16. The tool of claim 12, wherein the piston chamber is configured to hold a portion of the drilling fluid.
 17. The tool of claim 12, wherein the nozzle ring is configured to travel along the outer surface of the mandrel.
 18. The tool of claim 12, wherein the nozzle ring is configured to increase a pressure in the drilling fluid.
 19. The tool of claim 12, wherein the piston assembly comprises a seal located on an outside width of the nozzle ring configured to stop fluid flow between the piston's width and an inner surface of the piston chamber.
 20. The tool of claim 1, wherein at least a portion of the secondary fluid pathway is protected by a wear resistant material. 